diff --git a/BaseTools/Source/Python/GenFds/FfsFileStatement.py b/BaseTools/Source/Python/GenFds/FfsFileStatement.py
index 690826bcb9..f76ddf4d95 100644
--- a/BaseTools/Source/Python/GenFds/FfsFileStatement.py
+++ b/BaseTools/Source/Python/GenFds/FfsFileStatement.py
@@ -101,7 +101,7 @@ class FileStatement (FileStatementClassObject) :
                     MaxAlignValue = 1
                     for Index, File in enumerate(self.FileName):
                         try:
-                            f = open(File, 'r+b')
+                            f = open(File, 'rb')
                         except:
                             GenFdsGlobalVariable.ErrorLogger("Error opening RAW file %s." % (File))
                         Content = f.read()
diff --git a/BaseTools/Source/Python/GenFds/Fv.py b/BaseTools/Source/Python/GenFds/Fv.py
index 64d1709946..ab3f8b213b 100644
--- a/BaseTools/Source/Python/GenFds/Fv.py
+++ b/BaseTools/Source/Python/GenFds/Fv.py
@@ -182,7 +182,7 @@ class FV (FvClassObject):
         # Write the Fv contents to Buffer
         #
         if os.path.isfile(FvOutputFile):
-            FvFileObj = open ( FvOutputFile,'r+b')
+            FvFileObj = open ( FvOutputFile,'rb')
 
             GenFdsGlobalVariable.VerboseLogger( "\nGenerate %s FV Successfully" %self.UiFvName)
             GenFdsGlobalVariable.SharpCounter = 0
diff --git a/BaseTools/Source/Python/GenFds/FvImageSection.py b/BaseTools/Source/Python/GenFds/FvImageSection.py
index 748d02f700..5989978a7c 100644
--- a/BaseTools/Source/Python/GenFds/FvImageSection.py
+++ b/BaseTools/Source/Python/GenFds/FvImageSection.py
@@ -64,7 +64,7 @@ class FvImageSection(FvImageSectionClassObject):
             for FvFileName in FileList:
                 FvAlignmentValue = 0
                 if os.path.isfile(FvFileName):
-                    FvFileObj = open (FvFileName,'r+b')
+                    FvFileObj = open (FvFileName,'rb')
                     FvFileObj.seek(0)
                     # PI FvHeader is 0x48 byte
                     FvHeaderBuffer = FvFileObj.read(0x48)
@@ -109,7 +109,7 @@ class FvImageSection(FvImageSectionClassObject):
                 if self.FvFileName != None:
                     FvFileName = GenFdsGlobalVariable.ReplaceWorkspaceMacro(self.FvFileName)
                     if os.path.isfile(FvFileName):
-                        FvFileObj = open (FvFileName,'r+b')
+                        FvFileObj = open (FvFileName,'rb')
                         FvFileObj.seek(0)
                         # PI FvHeader is 0x48 byte
                         FvHeaderBuffer = FvFileObj.read(0x48)
diff --git a/BaseTools/Source/Python/GenFds/Region.py b/BaseTools/Source/Python/GenFds/Region.py
index e393286a16..945c5489fd 100644
--- a/BaseTools/Source/Python/GenFds/Region.py
+++ b/BaseTools/Source/Python/GenFds/Region.py
@@ -148,7 +148,7 @@ class Region(RegionClassObject):
                         EdkLogger.error("GenFds", GENFDS_ERROR,
                                         "Size of FV File (%s) is larger than Region Size 0x%X specified." \
                                         % (RegionData, Size))
-                    BinFile = open(FileName, 'r+b')
+                    BinFile = open(FileName, 'rb')
                     Buffer.write(BinFile.read())
                     BinFile.close()
                     Size = Size - FileLength
@@ -201,7 +201,7 @@ class Region(RegionClassObject):
                     EdkLogger.error("GenFds", GENFDS_ERROR,
                                     "Size 0x%X of Capsule File (%s) is larger than Region Size 0x%X specified." \
                                     % (FileLength, RegionData, Size))
-                BinFile = open(FileName, 'r+b')
+                BinFile = open(FileName, 'rb')
                 Buffer.write(BinFile.read())
                 BinFile.close()
                 Size = Size - FileLength